Search PubMed⌕ Search

Biomedical subjects

S Kawamura

Publications and source records attributed to S Kawamura.

At least 289 records · Page 16Linked to original sources
PubMed1991

Biphasic effects of yohimbine on the ejaculatory response in the dog.

The effects of various doses (0.01-1.00 mg/kg) of yohimbine, an alpha-2 adrenoceptor antagonist, on the erectile and ejaculatory response elicited by manual penile stimulation were investigated in male dogs. Systemic administration of yohimbine caused a biphasic effect on ejaculatory response; the amount of ejaculate produced by the genital stimulation (for 5 min) was dose-dependently increased by low doses (0.01-0.10 mg/kg) of yohimbine, whereas it was decreased by the highest dose (1.00 mg/kg) of yohimbine. The erectile potency was attenuated only, by the highest dose of yohimbine. The most effective dose (0.10 mg/kg) of yohimbine on ejaculation did not affect the duration of penile erection after removing the genital stimulation. In a stereoisomer's testing, the stimulatory effect on ejaculation was also observed by rauwolscine, an alpha-2 adrenoceptor antagonist (0.03 and 0.10 mg/kg), but not by corynanthine, an alpha-1 adrenoceptor antagonist (0.10 and 0.30 mg/kg). These results suggest that yohimbine at low doses specifically facilitate the ejaculatory response through the blockade of the alpha-2 adrenoceptors. This study also indicates that the effects of yohimbine on male genital responses vary with its dosage used.

Animals↗
PubMed1991

High energy underwater shock wave treatment on implanted urinary bladder cancer in rabbits.

The effects of focused high energy shock waves (SW) on the implanted urinary bladder cancer in rabbits were examined. The bladder cancer was exposed to 2000 to 8000 shots of focused SW under ultrasound guidance. Although only focal necrosis of the tumor was seen in the one day SW exposure, wider and deeper tumor necrosis was observed in the tumors following serial SW (2000 to 6000 shots, for two to three days). Eight to 10 day serial SW exposure (6000 to 8000 shots) decreased the tumor growth in comparison with that of the control. Lung metastases examined by periodic chest X-ray after SW treatment revealed that SW did not promote lung metastases. Pathological findings were also in accord with the X-ray examinations. Polyclonal antibody type 4 collagen was used for immunohistochemical staining of vascular wall in bladder cancer. Vascular wall destruction, not found in spontaneous necrotic tumor, were clearly visible in SW induced necrotic area. SW induces vascular damage in the tumor, which may be the primary cause promoting the tumor necrosis.

Animals↗
PubMed1991

Left preureteral vena cava (retrocaval or circumcaval ureter) associated with partial situs inversus.

We present a rare case of left preureteral vena cava associated with partial situs inversus. A 68-year-old woman was referred to our clinic for further study of left hydronephrosis on computerized tomography. The abdominal viscera were in mirror image and the heart was levocardia. The middle portion of the left ureter was dorsal to the left inferior vena cava. The left ureter was reanastomosed ventral to the inferior vena cava. To our knowledge, coexistence of preureteral vena cava and partial situs inversus has not been reported previously in the literature.

Aged↗
PubMed1991

Comparison of the clinical results of STA-MCA anastomosis and the medical treatment in the cerebral low perfusion patients with viable brain tissue.

The long-term clinical results of STA-MCA anastomosis as well as the medical treatments were compared in cases that were confined as having a focal cerebral perfusion deficit with viable brain tissue, based on either the drug induced EEG and evoked potential test (DEE test) and/or by positron emission tomography (PET). The criteria for viable cerebral tissue was determined by the following four conditions: (1) functional reversibility could be confirmed by the DEE test; (2) a haemodynamic process could be found in the DEE test; (3) a haemodynamic compromise could be confirmed in the PET study; (4) misery perfusion could be confirmed in the PET study. From 1975 to 1989, 55 cases were confirmed as having viable brain tissue according to the DEE test and the PET study. Of the 55 cases, bypass surgery was performed on 35. Conservative treatment was given to the other 20 cases. There were 3 cases of perioperative neurological deterioration. One was permanent and the other 2 were transient. Results of the long-term follow up are as follows, Ipsilateral attack: 1 case (2.0%) received surgery, and 7 cases (35%) received conservative treatment. Re-attack in the contralateral or posterior circulation: 6 cases (17.2%) received surgery, and 1 case (5%) received conservative treatment. Seventy-seven per cent of the surgical cases improved or had no change in the final functional status, while only 55% of the conservative group either improved or showed no change. The incidence of ipsilateral cerebral ischaemia was significantly low in the surgical group. Contralateral and/or posterior circulation ischaemia tended to be high in this group, however.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Evolutionary rate of immunoglobulin alpha noncoding region is greater in hominoids than in Old World monkeys.

Recent studies on the molecular evolution of primates show that the evolutionary rate among hominoids is considerably slower than that among nonhominoid primates. However, this observation at the nucleotide-sequence level is restricted to the beta-globin family region. In this study, we sequenced orthologous immunoglobulin alpha (C alpha) genes of chimpanzee, gorilla, orangutan, and crab-eating macaque (an Old World monkey) and compared them with that of the human by using noncoding regions for analysis. Since significant differences in rates among hominoids were not found by using the relative rate test, we evaluated the ratio (R) of the evolutionary distance between Old World monkey and human to the distance between orangutan and human. The R value (1.12) for the C alpha gene was much smaller than the expected value (1.38-2.33), showing that the nucleotide substitution rate (= mutation rate per year under selective neutrality) of the C alpha gene is greater in the human lineage than in the Old World monkey lineage. We also did a similar analysis for the gamma 1-, gamma 2-, psi eta-, and delta-globin genes and found a considerable heterogeneity (1.12-2.37) among the R values, including that for the C alpha gene. This indicates that the hominoid slowdown of the evolutionary rate is not a universal phenomenon in primate evolution.

Animals↗
PubMed1991

Early and delayed I-123 IMP SPECT in epileptic patients with partial seizures and normal CT.

Forty-six epileptic patients with partial seizures and normal CT underwent 48 examinations of early and delayed SPECT using I-123 IMP in the interictal phase. One of them underwent a follow-up SPECT in a more stable state compared to the first SPECT. Another patient, with informed consent, underwent a follow-up SPECT in combination with pharmacologic activation with bemegride. Early SPECT was performed 30 minutes after an IMP injection and delayed SPECT 4 to 4 1/2 hours later. Temporal changes in uptake pattern were visually classified into six types and compared with known patterns of SPECT uptake in relation to ischemic, hyperemic, and other changes. These were also correlated with the amount of epileptic activity seen on the EEG.

Adolescent↗
PubMed1991

Inhibition of the action of a stimulatory GDP/GTP exchange protein for smg p21 by acidic membrane phospholipids.

A stimulatory GDP/GTP exchange protein for smg p21 (smg p21 GDS) stimulated the dissociation of GDP from smg p21B. This reaction was inhibited by acidic membrane phospholipids such as phosphatidylinositol, phosphatidylinositol-4-monophosphate, phosphatidylinositol-4,5-bisphosphate, phosphatidic acid, and phosphatidylserine but not by phosphatidylcholine or phosphatidylethanolamine. These acidic phospholipids inhibited the smg p21 GDS action in a manner competitive with both smg p21 GDS and smg p21B. smg p21 GDS has other actions to inhibit the binding of smg p21B to membranes and to induce the dissociation of prebound smg p21B from the membranes. The acidic phospholipids also inhibited these two actions of smg p21 GDS. smg p21B has a polybasic region and an isoprenoid moiety in its C-terminal region which are necessary for its membrane-binding activity and its sensitivity to the smg p21 GDS actions. Therefore, it is possible that acidic membrane phospholipids interact with this polybasic region and thereby inhibit the smg p21 GDS actions.

Animals↗
PubMed1991

Amyloid enhancing factor (AEF). Isolation and biochemical and pathological characteristics.

Neutrophils and spleens were prepared from mice after treatment to induce amyloid deposition. The deposition of amyloid was accelerated in normal recipients by intravenous injection of more than 2 x 10(4) neutrophils, and intraperitoneal injection of supernatants obtained by homogenization and centrifugation of the neutrophils and spleens. The supernatants were subjected individually to DEAE ion-exchange chromatography. Amyloid enhancing factor (AEF) activity was present in peaks eluted at an NaCl concentration of 0.17 M. The fractions containing AEF were subjected to high-performance liquid chromatography (HPLC), and AEF was eluted at a position corresponding to about 15 KDa. Purified AEF was analyzed by amino acid sequencing and gas chromatography. The N-terminal amino acid was blocked, and AEF contained some saccharides including glucose, mannose, galactosamine and sialic acid, and an undefined substance (probably derived from certain proteins). Immunoelectron microscopy by the pre-embedding method using an anti-AEF antiserum demonstrated that the cytosol, but not primary and specific granules in neutrophils from the spleen of amyloid-laden mice, reacted with the antiserum. These findings suggest that AEF is a glycoprotein associated with neutrophils.

Amino Acid Sequence↗
PubMed1991

Renal involvement in POEMS syndrome.

We describe a patient with POEMS syndrome whose renal biopsy specimen also showed nephropathy. Immunoelectron microscopy of the renal biopsy revealed the localization of immunoglobulin (IgA and lambda light chain) in the subendothelial space of the glomerular capillaries, a previously unrecognized finding. We conclude that the renal pathology in POEMS syndrome is unusual and distinct from microangiopathic glomerular involvement or idiopathic mesangiocapillary glomerulonephritis.

Adult↗
PubMed1991

Successful repair of huge bladder diverticulum with a transurethral fulguration. Report of a case.

We present a 68-year-old man with a huge bladder diverticulum associated with benign prostate hypertrophy treated with transurethral fulguration of the diverticular mucosa in combination with transurethral resection of the prostate. The procedure was well tolerated by the patient and unfavorable symptoms faded after this procedure. Follow-up cystogram demonstrated remarkable reduction of the diverticulum.

Aged↗
PubMed1991

Action potential of the intramural ureter in the dog.

In 33 adult mongrel dogs, the function of the intramural ureter was investigated. (A) Bipolar electrodes were placed in both the extravesical ureter and the intramural ureter. Then, an electromyogram (EMG) was recorded from two leads. (B) Cystotomy was performed, needle-type electrodes were inserted into the wall of the ureteral orifice and the extravesical ureter, and the EMG was recorded. (C) A special needle which could record EMG and measure pressure simultaneously was prepared. Then EMG and pressure measurements were recorded from the wall of the intramural ureter. In each experiment, action potentials were recorded from the intramural ureter that were similar to those from the extravesical ureter. The pressure in the wall of the intramural ureter showed variations matching the action potentials. From these results, it was evident that active muscle contraction occurred due to the action potential transmitted from the extravesical ureter even in the intramural ureter.

Action Potentials↗
PubMed1991

Attenuated neuropathology by nilvadipine after middle cerebral artery occlusion in rats.

We investigated the effects of nilvadipine, a calcium antagonist, on cerebral ischemia in rats. Under halothane anesthesia, 30 rats had a 3-0 nylon suture introduced through the extracranial internal carotid artery to occlude the left middle cerebral artery. Nilvadipine was dissolved in polyethylene glycol 400. Immediately following occlusion, group 1 rats (n = 10) were treated subcutaneously with vehicle and group 2 and 3 rats were treated with 1.0 (n = 10) and 3.2 (n = 10) mg/kg nilvadipine, respectively. Perfusion fixation was performed 24 hours later, and the histopathologic outcomes were quantified. In group 1 infarct volume was 28.2 +/- 11.4% of the total cerebral volume; in groups 2 and 3 infarct volumes were 25.5 +/- 11.6% (NS) and 13.9 +/- 9.2% (p less than 0.05 different from group 1), respectively. Nilvadipine decreased ischemic neuronal injury in a dose-dependent manner and may be of use in the treatment of cerebral ischemia.

Animals↗
PubMed1991

Isolation and identification of clostridia from the intestine of laboratory animals.

Quantitative and qualitative examination of faecal clostridia from laboratory mice, rats, hamsters and rabbits was carried out by using selective as well as nonselective culture techniques. The 364 isolates were identified where possible, to species level on the basis of physiological and biochemical characteristics. Most isolates from mice and rabbits were identified, i.e. 79.4% and 76.5%, respectively, while only 25.4% and 28.6% of isolates from rats and hamsters were characterized as described species. The most common species of the 16 identified were: C. coccoides, C. cocleatum and C. innocuum from mice; C. cocleatum, C. cochlearium and C. irregularis from rats; C. cocleatum and C. irregularis from hamsters; and C. aminovalericum and C. irregularis from rabbits. Unidentified Clostridium spp. were isolated from each animal species tested and were tentatively classified into 26 groups. None of these groups was found in more than one animal species in this study.

Animals↗
PubMed1991

[The study on the function of the intramural portion of the ureter. The motion of the intramural portion of the ureter in dogs].

UNLABELLED: The present investigation was performed in order to clarify whether the motion of the intramural portion of the ureter is passive or active. In Experiment I, electromyograms of the extravesical and intramural portions of the ureter were recorded using bipolar suspended electrodes and bipolar needle electrodes for 52 ureters in 26 adult mongrel dogs to study the relationship between both portions of the ureters in the nondiuretic and diuretic state. In Experiment II, using 14 ureters in 10 adult mongrel dogs, electromyograms were recorded and the local forces of the ureteral walls of the extravesical and intramural portions were measured with a special needle electrode concurrently. RESULTS: (1) Experiment I demonstrated in the nondiuretic and diuretic state, 1. no significant differences in the ureteral discharge frequency between the extravesical and intramural portion of the ureters, and 2. a 1:1 correspondence in the extravesical and intramural action potentials. (2) Increases were observed in the local forces of the ureteral walls of the intramural portion of the ureters following action potentials. From these experimental results, it was suggested that the intramural portion of the ureter actively moves due to muscular excitation from the upper ureter and participates in urine transport.

Action Potentials↗
PubMed1991

[Whole layer needle biopsy for evaluation of neoadjuvant therapy to invasive bladder cancer].

The most important information for treatment of bladder cancer is to know its exact staging. A whole layer needle biopsy technique has been developed for this purpose. Recently, neoadjuvant therapy has been used for invasive bladder cancer. Although down staging of bladder cancer after neoadjuvant therapy are evaluated by CT or ultrasound, these imaging are not reliable. We examined 11 invasive bladder cancer patients by whole layer needle biopsy pre and post neoadjuvant therapy. All cases were pT3-4 by pretreatment biopsy. After neoadjuvant therapy 4 were changed to pT0 by needle biopsy, other cases were no change or minimal change. In 4 changed to pT0, 3 were done total or partial cyctectomy and the results of pathological diagnosis of cystectomized specimens were also pT0. Another one case changed to pT0 is selected as candidate for bladder sparing and the patient is now in close surveillance. All 4 cases changed to pT0 were done combined treatment by chemo (internal iliac artery infusion) and radiotherapy. In remaining 7 cases, pathological staging of surgical or autopsy specimen agreed with that of whole layer needle biopsy. Whole layer needle biopsy showed no severe complication, except minor bleeding from the bladder wall. Tumor seeding into the needle tract was not observed up to present time. In conclusion, this biopsy system is useful for evaluation of the change of stage with chemotherapy and/or radiation therapy. By using this technique we can select the cases for candidate of bladder sparing.

Aged↗